Clamp construction

ABSTRACT

A tong-type C-clamp having a pair of members pivotally connected to one another intermediate their ends with the portions of the members extending to one side of the pivotal connection comprising handle elements and the portions extending to the other side of the pivotal connection comprising clamping arms is provided with a quick grip lock and release cam means mounted on the clamping arm of one of the members adjacent the pivot connection. The cam means has a surface adapted to engage the edge of the handle portion of the other member to lock the clamp in clamping position and includes means to rotate the cam means between its locking and release positions.

0 United States Patent 1191 1111 Hultquist Mar. 11, 1975 [54] CLAMP CONSTRUCTION 2,526,085 10/1950 Rotollo 294 1 l8 2,613,103 101952 B h 11 294 106 [76] Inventor: John V. Hultquist, 836 Hayward St., us

Anahelm Calif 92804 Primary ExaminerEvon C. Blunk [22] Filed: Aug. 8, 1973 Assistant ExaminerJohnny D. Cherry 1 I [2 App] No 386,833 ABSTRACT A tong-type C-clamp having a pair of members pivot- [32] F.S.CCll. .1 294/1l862694/1l2g any Connected to one another intermediate their ends 2 i g with the portions of the members extending to one I l 0 side of the pivotal connection comprising handle ele- 29/283 81/370 5 ments and the portions extending to the other side of the pivotal connection comprising clamping arms is provided with a quick grip lock and release cam [56] References Cited means mounted on the clamping arm of one of the UMTED STATES PATENTS members adjacent the pivot connection. The cam 126,818 5/1872 Lindsay 294/118 UX means has a surface adapted to engage the edge of the 742,922 1 H1903 Snowden.... 294/106 X handle portion of the other member to lock the clamp 929,819 8/1909 Bertram 294/31 R i l i i i and i l means to rotate the 2,301,079 11/1942 Ph1pps 29/283 X cam means between its locking and reease positions. 2,305,054 12/1942 Ash 294/118 2,415,145 2/1947 Mollenhour 294/104 X 7 Claims, 2 Drawing Figures PATENTEI] MRI 1 I975 CLAMP CONSTRUCTION INTRODUCTION This invention relates to clamps and more particularly relates to a C-clamp construction having a quickgrip and release means thereon greatly enhancing its use in a wide variety of applications.

BACKGROUND OF THE INVENTION C-clamps have long been in widespread use for everything from wood clamps to ice tongs to glass pane carriers. One of the most conventional kinds of such clamps, and the kind with which this invention is concerned, is the conventional tong-type construction, e.g., U.S. Pat. Nos. 2,100,497 and 2,305,054. In this construction a pair of members are pivotally connected to one another intermediate their ends, the portions of the members extending in one direction from the pivot connection serve as handles for the clamp and the portions of the members extending in the other direction from the pivot connection serve as the clamping arms. The clamping arms are usually C-shaped to accommodate different shaped workpieces therebetween and terminate at their ends in jaws that clamp the workpiece therebetween. The operation of the clamps is basically quite simple. As the handles are moved toward one another the clamping arms correspondingly move together; thus, in a lifting operation, the heavier the workpiece, the more force exerted in moving the handle extremities toward one another and the tighter the grip exerted on the workpiece by the clamp jaws as the workpiece is lifted by the clamp.

Such tong-type clamps have been provided with locking mechanism to maintain the clamp in a set locked position so the workpiece will not be released as it is being handled. Usually these locking mechanisms are somewhat elaborate and applied to the handle portions of the clamps, for example, as illustrated in U.S. Pat. Nos. 2,301,079 and 2,705,659. The present invention provides a tong-type C-clamp having a greatly improved clamp locking means.

BRIEF INVENTION DESCRIPTION The present invention provides a tong-type C-clamp having a quick lock and release mechanism which acts directly upon the clamping arms of the clamp while adding very little bulk or weight to the clamp and which means is operable with the simple flick of a lever to grip or release.

This new C-clamp construction greatly enhances the utility of tong-type C-clamps and provides an ideal clamping construction for such heavy duty work as automobile body and frame straightening, much of which is now done with screw-type locking clamps wherein the jaws ofthe clamp are held in place by screw mechanisms ofone kind or another as illustrated, for example, in U.S. Pat. Nos. 2,059,972, 3,241,352, and 3,696,653. The simplified tong-type C-clamp construction of this invention adapts this clamp admirably for automobile panel and for heavy duty frame straightening operations and provides a particularly valuable clamping mechanism for assisting in the straightening of automobile body panels as used in the so-called unitized frame automobile construction wherein the automobile frame forms the basic shell for the entire automobile body with the facing panels welded thereto. The quick lock and release clamp of this invention enables quick and bend out of the panel or other workpiece being worked on and enables rapid release and emplacement of the clamp in adjacent or other position as the straightening operation proceeds. The clamp of this invention, however, is clearly not limited to such use and by its simple construction and readily actuable lock and release mechanism can be advantageously employed in almost any operation where tongs or C-clamps can be used.

The C-clamp of this invention comprises a pair of clamping members pivotally connected or attached to one another intermediate their ends with the portions of the members extending in one direction from the pivotal connection being generally C-shapcd clamping arms terminating at their ends in facing clamping jaws, the portions of the members extending in the other direction from the pivotal attachment comprising handle elements. Cam means are carried by one of the clamping arms adjacent the pivotal connection and the cam means are engageable with the other clamping arm to hold the clamping jaws in position upon clamping of a workpiece therebetween. The cam means are actuated by a lever directly connected thereto so that the clamp is placed in grip locking position or released therefrom by a simple flip of the lever to engage or release the cam means.

DETAILED INVENTION DESCRIPTION The invention is described in more detail hereinafter in connection with the accompanying drawings wherein:

FIG. 1 is a front view of the clamp of the invention in its locked clamping position; and

FIG. 2 is a side view of the clamp of FIG. 1.

The C-clamp of the invention is designated in its entirety by the numeral 10 and is seen to comprise a pair of clamping members 12 and 14 pivotally attached to one another by means of the pivot connection 16, which in the drawing takes the form of a bolt and nut connection. The portions of the clamping members 12 and 14 to one side of the pivot connection 16 (portions which extend in one direction from the pivot point) which are C-shaped comprise clamping arms 18 and 20, respectively. These clamping arms terminate in facing clamping jaws 22 and 24, respectively. The portions of the members 12 and 14 extending to the other side of the pivot connection 16 designated as 26 and 28, respectively, comprise the handle elements of the clamp 10. The end portions of the handle elements 26 and 28 have holes 27 and 29 therein, respectively, carrying rings 30 and 32, respectively for the attachment of the handles to a pulling member such as hook 42 on chain 44. Clamping arm 20 is provided with a flat disc-like oval cam 34 adjacent the pivot connection 16 of the clamping arms 18 and 20 to one another. The cam 34 is pivotally attached by means of the pin 36 in an off center position, the pin extending through an aperture (unnumbered) in the clamping arm 20 for rotational movement therein and being fixed to cam 34. A lever 38 is fixedly attached to pin 36.

The operation of the C-clamp of the invention is quite straightforward. A workpiece or plate to be straightened or load to be lifted 40 is placed between the jaws 22 and 24 of the clamp while the cam and lever are in the position shown in dotted outline in FIG. 1. Then, the lever is swung downwardly to the full-line position so that the curved edge surface of the cam engages the handle portion 28 of the clamping member 14 adjacent the pivotal connection 16 to lock the gripped workpiece 40 in place. Thereafter the workpiece may be pulled, lifted or otherwise handled as desired, as, for example, through the medium of the hook and chain arrangement illustrated. To release the clamp from its locking position, the lever 38 is simply flicked back toward its dotted line position. Thus. the clamp can be emplaced, moved, locked and released quickly and with great precision by the user thereof.

As'will be observed, the cam means 34 is rotatably mounted on the clamping arm 20 of the member 12 adjacent the pivot connection 16 and has a surface adapted to engage the edge of the handle portion 28 of the other member 14 of the clamp. It is this relation of the cam means to the clamping arm of the one member and to the handle of the other member which provides the simplicity of quick grip and release inherent in the construction, the cam means being on one side of the pivotal connection and the edge surface of the handle engaged by the same surface being on the other side of the pivotal connection.

What is claimed is:

l. A C-clamp comprising a pair of clamping members pivotally attached to one another intermediate their ends, the portions of said members to one side of the pivotal attachment comprising generally C-shaped arms terminating in facing clamping jaws, the portions of said members to the other side of the pivotal attachment comprising handle elements, cam means movably carried by the arm of one of said members for engagement with the handle element of the other of said members to hold the clamping jaws in clamped position upon clamping a workpiece therebetween.

2. A clamp in accordance with claim 1 wherein said cam means comprises a cam pivotally attached to said one arm adjacent to and on an axis parallel with that of the pivotal attachment of said arms to one another, said cam having a curved peripheral surface and said other arm having a surface adapted to abut therewith.

3. A clamp in accordance with claim 2 wherein said cam has a lever arm thereon for moving it between its inactive and clamp holding positions.

4. In a tong-type C-clamp comprising a pair of members pivotally connected to one another intermediate their ends with the portions thereof extending to one side of the pivotal connection comprising handle ele-. ments and the portions thereof extending to the other side of the pivotal connection comprising clamping arms terminating in elampingjaws for clamping a workpiece therebetween, the improvement comprising a cam means rotatably mounted on the clamping arm of one of said members adjacent the pivotal connection and having a surface adapted to engage the edge of the handle element of the other of said members to position and maintain the clamp in gripping position. and means carried by said cam means for rotating said cam means to move said cam surface into and out of engagement with said other handle element.

5. The clamp of claim 4 wherein said cam means comprises a flat disc-like oval, the curved edge surface thereof being adapted to engage the edge of said handle element to maintain the clamp in gripping position.

6. The clamp of claim 4 wherein said cam means comprises a flat disc-like oval, the curved edge surface thereof being adapted to engage the edge of said handle element to maintain the clamp in gripping position, and said cam means including a lever arm fixed to said oval for moving said cam means into and out of engagement with the handle element.

7. A clamp comprising a pair of members one crossing over the other intermediate the ends of the members, means pivotally connecting said members to one another where they cross over, the portions of said members extending to one side of the pivotal connection comprising handle elements and the portions of said members extending to the other side of said pivotal connection comprising clamping arms, the extremities of said clamping arms including means for clamping a workpiece therebetween, cam means, and means pivotally mounting said cam means on the clamping arm of one of said members adjacent said pivotal connection, said cam means being adapted to engage the handle element of the other of said members to position and hold the clamping arms in clamped position on a workpiece disposed therebetween. 

1. A C-clamp comprising a pair of clamping members pivotally attached to one another intermediate their ends, the portions of said members to one side of the pivotal attachment comprising generally C-shaped arms terminating in facing clamping jaws, the portions of said members to the other side of the pivotal attachment comprising handle elements, cam means movably carried by the arm of one of said members for engagement with the handle element of the other of said members to hold the clamping jaws in clamped position upon clamping a workpiece therebetween.
 1. A C-clamp comprising a pair of clamping members pivotally attached to one another intermediate their ends, the portions of said members to one side of the pivotal attachment comprising generally C-shaped arms terminating in facing clamping jaws, the portions of said members to the other side of the pivotal attachment comprising handle elements, cam means movably carried by the arm of one of said members for engagement with the handle element of the other of said members to hold the clamping jaws in clamped position upon clamping a workpiece therebetween.
 2. A clamp in accordance with claim 1 wherein said cam means comprises a cam pivotally attached to said one arm adjacent to and on an axis parallel with that of the pivotal attachment of said arms to one another, said cam having a curved peripheral surface and said other arm having a surface adapted to abut therewith.
 3. A clamp in accordance with claim 2 wherein said cam has a lever arm thereon for moving it between its inactive and clamp holding positions.
 4. In a tong-type C-clamp comprising a pair of members pivotally connected to one another intermediate their ends with the portions thereof extending to one side of the pivotal connection comprising handle elements and the portions thereof extending to the other side of the pivotal connection comprising clamping arms terminating in clamping jaws for clamping a workpiece therebetween, the improvement comprising a cam means rotatably mounted on the clamping arm of one of said members adjacent the pivotal connection and having a surface adapted to engage the edge of the handle element of the other of said members to position and maintain the clamp in gripping position, and means carried by said cam means for rotating said cam means to move said cam surface into and out of engagement with said other handle element.
 5. The clamp of claim 4 wherein said cam means comprises a flat disc-like oval, the curved edge surface thereof being adapted to engage the edge of said handle element to maintain the clamp in gripping position.
 6. The clamp of claim 4 wherein said cam means comprises a flat disc-like oval, the curved edge surface thereof being adapted to engage the edge of said handle element to maintain the clamp in gripping position, and said cam means including a lever arm fixed to said oval for moving said cam means into and out of engagement with the handle element. 